not in cold spring, texas. that's where a few years back a school janitor named murray burr was murdered, stabbed dozens of times in his home, and this young woman, meg began winfrey was convicted of the killing because a dog by scent alone put her at the murder scene. now she's in prison serving a life sentence. >> the dog scent thing, that's the biggest joke there ever was. >> reporter: her father, richard, was stunned that the evidence stood up. after all, he and meg began's brother were also identified as suspects by that dog. but the courts dropped the charges after deciding the dog evidence was fatally flawed. >> i just can't believe that that's even thought of, that they can take somebody's life away over a dog. >> reporter: so how are dogs trained for so-called scent lineups? professional trainer and police officer, david vladimir gave us a demonstration with some unused pizza boxes. at a crime it may be bits of clothing from suspects and others would be placed where a dog could only smell them. >> we'l